Your MX record exposes your origin IP - What does this mean?

If you are hosting your own mail server and this is located on the same webserver as your website you will receive the message “Your MX record exposes your origin IP”. This means that attackers can learn the location of your server through your MX records and therefore learn where your website is hosted.

As an example: 

Simple link to another page Another link Another link And here is a broken link Broken link again